Changes with time in the migration of radiocesium in the soil, as observed near Chernobyl and in Germany, 1986-1994
Changes with time in the migration of radiocesium in the soil, as observed near Chernobyl and in Germany, 1986-1994
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DOI：
10.1016/0048-9697(95)04842-1
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发表时间：
1995-12-08
影响因子：
9.8
通讯作者：
Alexakhin, RM
中科院分区：
文献类型：
--
作者：
Bunzl, K;Schimmack, W;Alexakhin, RM
在切尔诺贝利核电站（ChNPP）的近场草地网站和在草地网站在德国的平均滞留半衰期的来源于铯-137的各种土壤层作为时间的函数。为此目的，每年观察到的垂直分布的这种放射性核素在土壤中进行了评价与分区模型。这两个网站之间的放射性铯的迁移的主要区别是明显的，在土壤表层，在1987年和1994年之间的停留半衰期增加在德国网站从约0.7年至2年，而它减少在中国核电厂网站从约9年至3年。在较深的土层中，两个地点的停留半衰期均随时间的增加而增加，并以相当相似的方式随深度而减少。在两个站点的顶部土壤层中的停留半衰期的相反行为的结果，这是因为Cs-137主要以不溶性燃料颗粒的形式沉积在中国核电站站点，而在德国站点，这种放射性核素以更容易获得的形式附着在天然气溶胶中。Cs-137滞留半衰期随时间的增加，在两个网站在较深的层可以解释由土壤的粘土矿物的放射性铯的逐步固定。
At a near-field grassland site at the Chernobyl nuclear power plant (ChNPP) and at a grassland site in Germany the mean residence half-times of Chernobyl-derived Cs-137 were determined for various soil layers as a function of time. For that purpose, the annually observed vertical distributions of this radionuclide in the soil were evaluated with a compartment model. The main difference between these two sites with respect to the migration of radiocesium was apparent in the top soil layer, where the residence half-time increased at the German site between 1987 and 1994 from about 0.7 to 2 years, while it decreased at the ChNPP site from about 9 to 3 years. In the deeper soil layers the residence half-times increased at both sites with increasing time and decreased with depth in a rather similar way. The opposite behavior of the residence half-time in the top soil layer at the two sites results from the fact that Cs-137 was deposited at the ChNPP site predominantly in the form of rather insoluble fuel particles, while at the German site this radionuclide was attached in a more available form to natural aerosols. The increase of the Cs-137 residence half-times with time at both sites in the deeper layers can be explained by the progressive fixation of radiocesium by clay minerals of the soil.